By letter dated February 24, 2000, the Tennessee Valley Authority (TVA)
requested that the U.S. Nuclear Regulatory Commission (NRC)
exercise enforcement discretion not to enforce compliance with certain
requirements of Technical Specification (TS) Surveillance Requirement
(SR) 3.3.2.10, "ESFAS Response Times." The letter documented information
previously discussed with the NRC staff in a telephone conference call
on February 23, 2000, starting at 1:00 p.m. The principal NRC staff members
who participated in that telephone conference call included R. Emch, L.
Wiens, R. Hernan, C. Schulten, W. Lyon, P. Fredrickson, D. Rich, and P.
Fillion. You stated that, based on an unforseen situation that had been
revealed as discussed below, entry into TS Limiting Condition for Operation
3.0.3 would be necessary at 5:00 p.m. (1700 hours) on February 23,
2000, and would require the Watts Bar Nuclear Plant (WBN), Unit 1, to
be shut down.

You requested that a Notice of Enforcement Discretion (NOED) be issued
pursuant to "NRC's General Statement of Policy and Procedures for NRC
Enforcement Actions" (Enforcement Policy), NUREG-1600, and be effective
starting at 5:00 p.m. on February 23, 2000, for a period of 30 days. This
letter documents our verbal approval of the NOED, which was the subject
of a second telephone conference call at 2:00 p.m. on February 23, 2000.
In that call, we orally issued this NOED for the period stated above and
conditioned on a TVA commitment to submit a formal TS change request by
February 25, 2000, to alleviate the deviation from the TS on a one-time
basis.

The WBN engineering staff was reviewing a work package for a future plant
modification. During the course of this review, the engineer discovered
that response time testing (RTT) had not been performed for the Train
B turbine trip solenoid valve (1-FSV-47-027-B) during WBN's Unit 1 Cycle
2 Refueling Outage in Spring 1999. This surveillance (SR 3.3.2.10) is
required by TS Limiting Condition for Operation (LCO) 3.3.2, Engineered
Safety Features Actuation System (ESFAS) Function 5(b), Steam Generator
Water Level High-High, on a frequency of 36 months. Because of this discovery,
WBN Unit 1 entered TS SR 3.0.3 on February 22, 2000, at 5:00 p.m.
As a result of this entry into SR 3.0.3, WBN was required to complete
performance of the subject SR within 24 hours (e.g., by 5:00 p.m. on February
23, 2000) or declare the Steam Generator Water Level function inoperable
and enter the appropriate TS Condition. In this case, the appropriate
TS after the 24-hour period allowed for performance of the SR would be
LCO 3.0.3, which requires action to be initiated within 1 hour to place
the unit in Mode 3 within the next 7 hours. Performance of SR 3.3.2.10
cannot be performed at full power since initiation of a turbine trip is
required. During the telephone conference call, TVA stated that the plant
must be in Mode 3 to perform this surveillance and concluded that shutting
down the unit to perform the subject surveillance introduces an unnecessary
plant transient that would not be commensurate with the public health
and safety for the given condition.

Solenoid valve 1-FSV-47-027-B trips the main turbine from a Train B feedwater
isolation signal from the Train B reactor protection system. In its NOED
request of February 24, 2000, TVA stated that, during the last plant refueling
outage, this solenoid was replaced as part of a preventive maintenance
(PM) activity. The post-maintenance test (PMT) procedure for this PM only
specified functional testing and did not specify a response time test.
However, this solenoid valve is part of the response time test for the
Train B Turbine Trip/Feedwater Isolation from the High-High Steam Generator
Level engineered safety feature (ESF) function. Because the solenoid valve
was replaced, the applicable portion of the Train B response time test
should have been performed. The response time tests are run on a train-staggered
basis. The Train B response time test was run during the previous outage,
Refueling Outage 1, and the Train A response time test was run during
the last outage, Refueling Outage 2. Because the response time of
this component is not quantitatively known, the overall response time
of the Train B Turbine Trip from High-High Steam Generator Level is also
not quantitatively known. The apparent root cause of this event appears
to be an inadequate PMT procedure.

During discussions between TVA and WBN's Nuclear Steam Supply System
(NSSS) vendor, Westinghouse, regarding their qualitative review of the
WBN Feedwater Malfunction analysis, Westinghouse stated that they model
turbine trip and feedwater isolation off of the steam generator high-high
water level setpoint, with a 2.5 second response time for turbine trip.
The event is analyzed primarily to demonstrate that the Departure from
Nucleate Boiling (DNB) design basis is satisfied. The minimum DNB Ratio
(DNBR) in the current WBN analysis occurs prior to the time of turbine
trip. In addition, the DNBR remains relatively constant up until the time
of the turbine trip and is well above the safety analysis limit DNBR.
Therefore, an increase in response time would not result in a more limiting
condition for this analysis, but would only delay the time that the event
is terminated. Even if the turbine trip does not occur, the feedwater
isolation signal would cause the steam generator to drain down and the
transient would simply behave as a loss-of-normal feedwater/inadvertent
emergency core cooling system (ECCS) at power event. The resultant transient
would be bounded by the existing Final Safety Analysis Report (FSAR) analyses.

In its request, TVA stated that the turbine trip function in question
is an equipment protection function, as described in the TS Bases. This
function prevents possible damage to the turbine due to water in the steam
lines. TVA's position is that failure to obtain response time data for
the Train B solenoid does not pose an issue of safety significance.

As discussed during the February 23, 2000, conference call, TVA submitted
an exigent license amendment request on February 25, 2000, which would
revise the WBN TS on a temporary one-time basis to delete applicability
of SR 3.3.2.10, "Turbine Trip and Feedwater Isolation," for the period
February 23, 2000, until restart of the main turbine following the next
time the main unit turbine is removed from service.

On the basis of the NRC staff's evaluation of your request, we have concluded
that a NOED is warranted because we are clearly satisfied that this action
involves minimal or no safety impact, is consistent with the enforcement
policy and staff guidance, and has no adverse impact on public health
and safety. Therefore, it is our intention to exercise discretion not
to enforce compliance with TS SR 3.3.2.10, as required by Function 5.b
of TS Table 3.3.2-1, for the period from 5:00 p.m. on February 23, 2000,
until 5:00 p.m. on March 24, 2000, or until the TS revision requested
by TVA letter dated February 25, 2000, is issued by the NRC, whichever
occurs first. The staff plans to complete its review and issue the license
amendment within 4 weeks of the date of this letter.

As stated in the Enforcement Policy, action will be taken, to the extent
that violations were involved, for the root cause that led to the noncompliance
for which this NOED was necessary.